How to remake BloC and add different states to show CircularProgressIndicator?-CodePudding

I have a BloC through which I receive data. But I ran into the problem that there are no different states so that I can display the loading indicator and handle errors if there are any. Can you tell me how can I modify this BloC class to have different states MyCarsLoading, MyCarLoaded so that I can display the loading indicator in the appropriate state?

bloc

class MycarsCubit extends Cubit<MycarsState> {
  MycarsCubit()
      : super(MycarsInitial(
          number: '',
          type: '',
        ));

  String number = '';
  String type = '';

  void clear() {
    number = '';
    type = '';
  }

  void change({
    required String numberText,
    required String typeText,
  }) {
    number = numberText;
    type = typeText;
    emit(MycarsInitial(
      number: number,
      type: type,
    ));
  }
}

state

abstract class MycarsState {}
 
class MycarsInitial extends MycarsState {
  String number;
  String type;

  MycarsInitial({
    required this.number,
    required this.type,
  });
}

CodePudding user response：

I usually do this using the freezed package with cubit, but without that you could do something like this:

class MycarsState extends Equatable {
  final String number;
  final String type;

  const MycarsState._({
    this.number = '',
    this.type = '',
  });

  const MycarsState.initial() : this._();

  const MycarsState.loading() : this._();

  const MycarsState.loaded({required String number, required String type})
    : this._(number: number, type: type);
    
  @override
  List<Object> get props => [number, type];
}

Then you can do like this:

 void change({
    required String numberText,
    required String typeText,
  }) {
    emit(const MycarsState.loading());

    number = numberText;
    type = typeText;

    emit(MycarsState.loaded(
      number: number,
      type: type,
    ));
  }

CodePudding user response：

https://bloclibrary.dev/#/flutterweathertutorial?id=weather-state You can see here how it is handled.